ELECTRODEPOSITION OF HARD CHROMIUM ON THE INTERIOR SURFACE OF INFANTRY RIFLE BARRELS: AN EXPERIMENTAL INVESTIGATION

Authors : Uğur Temel Yildiz, Temel Varol, Serhatcan Berk Akçay, Gençağa Pürçek

Pages : 66-69

View : 68 | Download : 58

Publication Date : 2023-12-31

Article Type : Research

Abstract :The objective of this study was to enhance the properties of the inner surface of a rifle barrel. The substrate utilized in this investigation was produced through the cold forging technique using 42CrMo4 material, measuring 260 mm in length and 5.56 mm in diameter. Electrolytic hard chromium plating was employed to create a durable metal layer on the inner surface of the substrate. A peristaltic pump was utilized to eliminate gases, such as hydrogen and oxygen, which evolved at the cathode and anode during the process. An anode material comprising a steel rod coated with a 93% Pb-7% Sn alloy, possessing a diameter of 2.35 mm, was employed in the coating experiments. Vickers hardness testing was performed to measure the hardness of both the substrate and the coating layer. The coating thickness ranged approximately between 23 µm to 30 µm. Hardness analysis conducted at various points indicated a proportional decline in coating microhardness with increasing coating thickness. Following the electrolytic hard chrome plating process, the inner surface hardness of the barrel reached approximately 1143 HV0.025.
Keywords : Barrel, Electroplating, Hard Chromium, Surface Coating, Steel